The Anger Management star said he was "joking" when he tweeted on Sunday that he had married the 24-year-old.
"I wanted to give Denise [Richards] a stroke!!!" he told TMZ, referring to his ex-wife. The hellraising actor told Twitter followers that he and girlfriend Brett had tied the knot during their holiday in Iceland, which would make her his fourth wife.
Charlie, 48, posted a picture of the couple together outside the former French consulate building in Reykjavík, where a 1986 Cold War summit was held between Ronald Reagan and Mikhail Gorbachev.
His caption read: "'This is the house ware M Gorbachev R Reagan did some epic. it's also where S and I GOT MARRIED!" S refers to 24-year-old Brett, whose nickname is Scottie.
Charlie added the hashtag: "RumorMilUhPede". His beloved only added to the suspicion that it was all a big joke with her comments.
When one of her Twitter followers talked about the nuptials, she responded: "Hahahahahahahahahahaha epic."
Another post showed the 'newlyweds' embracing in front of a fire extinguisher. Alongside it, Charlie had written: "It's like screaming "Theater, in a crowded Fire!!"get over me,or get yuse to"Us"...
The wedding Tweet was followed by another showing the Anger Management star getting a Jaw tattoo, with his 'wife' holding his hand. The etching was the work of renowned tattoo artist Gary James.
Charlie has been married three times before to Donna Peele, Denise Richards and most recently to Brooke Mueller. He has five children.